Many types of spinal irregularities can cause pain, limit range of motion, or injure the nervous system within the spinal column. These irregularities can result from, without limitation, trauma, tumor, disc degeneration, and disease. Often, these irregularities are treated by immobilizing a portion of the spine. This treatment typically involves affixing a plurality of fixation devices to one or more vertebrae and connecting the devices to an elongate rod that generally extends along the length of the spine.
Treatment for these spinal irregularities often involves using a system of fixation devices to attain stability between spinal segments. Instability in the spine can create stress and strain on neurological elements, such as the spinal cord and nerve roots. In order to correct this, various implants can be used to restore the correct alignment and position of the vertebral bodies. In some cases, a stabilization device, optionally in conjunction with a vertical solid member, can help restore and/or correct the alignment of spinal segments, thereby reducing pain or preventing further injury to the spine.
Stabilization devices may include a bone fastener, such as a screw, for fastening the device to vertebra. Some stabilization devices further may include a coupling element (e.g., a tulip element) for coupling the bone fastener to the vertical solid member (e.g., elongate rod). Clamp and/or wedge elements may be used to secure the bone fastener in the coupling element. A locking cap may also be used to secure the rod in the coupling element.